HCV prevalence shows the number of people in San Francisco who have been exposed to HCV. This prevalence statistic is based on reactive antibody tests, meaning that it includes people who have active HCV infections, people who had HCV but cleared it on their own, and people who had HCV but cleared it through treatment. A downward trend in this curve is desirable because it means fewer people in San Francisco are living with HCV over time and shows us if the city's efforts are effective at reducing HCV. This estimate also serves as a baseline as we evaluate and measure the progress of our work going forward.